One Pot Three Component Synthesis of Indole with Fused Chromenes Using an Efficient Tricaprylmethyl Ammonium Thiosalicylate Based Task Specific Ionic Liquids

This paper deals with the synthesis and characterization of a novel task specific ionic liquid (TSIL) using green chemicals such as tricaprylmethyl ammonium chloride (TCMA) and salicylate via an anion metathesis reaction and characterization by 1H-NMR technique. Also, a method for the synthesis of indolyl chromenes has been accomplished by the one-pot three component reaction of salicyaldehyde and malononitrile with indole catalyzed by simple and efficient methyltricaprylammoniumthiosalicylate based ionic liquids. The proposed TSIL was recovered and reused for half a dozen times without potential loss in its efficiency. This work also describes the in vitro antioxidant activity of indolyl chromenes as potential antioxidants. Most of the compounds assayed showed excellent reducing power and free radical scavenging activities.